Facile low-temperature synthesis of a hierarchical Sn-SnO₂/CNT/rGO composite for anode material in lithium-ion batteries

Carbon composites containing mixed Sn phases, such as Sn/SnO_x (x = 1 or 2), are considered promising anode materials for lithium-ion batteries due to the high capacity of Tin oxide (SnO_x) as well as the high electrical conductivity of metallic Sn. However, their preparation methods are often complicated and time-consuming. In this work, a facile low-temperature synthesis method has been developed to fabricate a Sn-SnO₂/CNT/rGO composite with nanosized Sn mixed phases and a hierarchical structure. TEM and SEM characterizations clearly confirmed highly dispersed Sn/SnO₂ particles of less than 10 nm and a porous structure with a high specific surface area. As a result of the specially designed structure and unique mixed phases, this composite exhibits a high lithium storage capacity of 1224 mAh g⁻¹ at 0.1 A g⁻¹ after 150 charge/discharge cycles. Furthermore, due to the well-developed hierarchical texture, which offers fast channels for the transport of Li⁺ and electrons, an outstanding rate performance of 798 mAh g⁻¹ at 1 A g⁻¹ is also achieved with high recoverability. Therefore, this research not only presents a high-performance anode material for advanced LIBs but also offers a viable method for preparing graphene-based mixed-phased metal/metal oxide composites.